Osteogenesis imperfecta (OI) is a hereditary disorder characterized by increased tendency for bone fractures due to high fragility. The clinical and radiological features of OI manifest in different age groups, although the disease is congenital in nature. Besides bone fragility, features like laxity of the ligaments, blue sclera, growth retardation, and scoliosis are also observed. In severe cases, respiratory distress and death have been reported. The most important oral finding in OI is the presence of yellowish-brown-coloured brittle teeth characteristic of dentinogenesis imperfecta. Genetic factors play a very important role in the pathogenesis of OI either as a dominant or recessive factor. When a child has OI, there is a 25% chance of the sibling to have the same disorder. We report two cases of OI in siblings born to parents with a history of consanguineous marriage. The clinical and radiological features of the two cases are described in detail.
Osteogenesis imperfecta (OI) is a disorder characterized by bone fragility and with severe deformities [
The most widely accepted classification was proposed by Sillence et al. in 1979 [
We report two cases of type IV B osteogenesis imperfecta in siblings with dental findings.
A 4-year-old male child was brought to the general hospital with complaints of bowed upper and lower limbs. The patient had history of fractures due to minor trauma during the past 2-3 years. The patients elder sibling had similar problem. There was a history of consanguineous marriage. The fractures were treated by local specialists, but after treatment, bowing of the upper and lower limbs were noticed. The patient had growth deformity and abnormally large head with frontal bossing (Figure
Clinical photograph of the patient showing brachycephalic head and frontal bossing.
Intraoral photograph showing yellowish discolouration and chipping of the dentition.
Chest radiograph showing long and narrow thorax (barrel-shaped chest) with anterior compression.
Radiograph of the upper limb showing bowing of the radius and ulnar.
Patient’s elder brother who was 10 years old had a deformed growth with bowing in the upper and the lower limbs. He also reported of multiple fractures and frequent joint dislocations secondary to minor trauma. The dental findings were identical to that of the younger sibling, but there was no evidence of delayed eruption (Figure
Intraoral photograph of the elder sibling showing yellowish discolouration of the dentition.
Radiograph of the lower limbs showing bowing of the femur, with widening of the metaphases.
Radiograph showing bowing tibia and fibula.
Osteogenesis imperfecta (OI), also known as “brittle bone disease”, is a heterogeneous group of genetic connective tissue-associated disorders [
Three scenarios that occur to cause a child to be born with OI [ Direct inheritance from a parent: 50% chance of passing on the disorder to next generation. A new dominant mutation: the gene spontaneously mutated in either the sperm or the egg before the child’s conception. Mosaicism: clinically unaffected parents with more than one affected child. The mutation occurred during the parent’s fetal development.
Siblings in our case exhibited clinical feature of Sillence Type IV OI characterized by brittle bones, growth retardation, pathologic fractures, and DI. More severe forms of OI tend to manifest at a very young age and have poor survival rates. The moderate forms such as Sillence’s Type IV has better survival rate as seen in our cases [